This invention relates to a recording and playing-back device, more particularly, to a recording and playing-back device which record a digital video image and audio or user data on a disk media such as a magneto-optical disk, a phase change disk, or a magnetic disk in order to play back the digital video image and audio or the user data.
As a conventional read only device for reading digital video data recorded on a disk, a digital versatile disk device (to be referred to as a DVD hereinafter) is known. The DVD is a disk, having a diameter of 12 cm, on which 4.7-Gbyte compressed digital video/audio data is recorded. When the data is read, video/audio signals can be played back for two or more hours. Similarly, as a device for recording/playing-back digital data on a disk, a digital versatile disk random access memory device (to be referred to as a DVD-RAM hereinafter) exists. This DVD-RAM is a device for recording 2.6-Gbyte digital data on a phase change disk having a diameter of 12 cm. A user can repeatedly record and play back the digital data from the disk.
By the way, navigation data may exist in the DVD. The navigation data is not video/audio data itself, and is disk management information which makes the video/audio data of the disk maximally effective. The disk management information is recorded on the entire surface of the disk once or a plurality of times, and has the following contents.
(1) A specific position where a program is stored, and the type of this program. The relationship between a program number and an address in header searching is recorded.
(2) Data for special play-backs (fast play-back, rewind play-back, and slow-motion play-back). Data which represents the number of times of a speed at which the head is jumped to the next address, and represents the next address is recorded.
(3) A specific address at which data is preferably played back when a multi-language (Japanese and English) is selected.
(4) A specific address at which data is preferably played back when a multi-angle (directions to the center fielder and the catcher in a broadcast on a baseball game) is selected.
(5) A specific address at which data is preferably played back when a multi-story (happy ending and sad ending) is selected.
When the DVD is a read only disk, the navigation data is not changed once the navigation data is recorded on the DVD. If the disk is programmable, the data can be changed. Data which can not be really used also exists on the disk. For example, in cases of the above-mentioned (1) and (2), since video/audio data is a variable length code, when the video/audio data is updated, the navigation data must be updated over a wide range. In cases of the above-mentioned (3), (4), and (5), multi-data cannot be recorded on real time in consideration of play-back synchronization. More specifically, the navigation data is made in consideration of a read only disk, but is not made in consideration of updating. With respect to a DVD-RAM, although an example of recorded video data is described above, video recording is not actually considered, and the concept of navigation data for recording video data does not exist.